using ComputerStoreContracts.BindingModels;
using ComputerStoreContracts.BusinessLogicContracts;
using ComputerStoreContracts.SearchModels;
using ComputerStoreContracts.StorageContracts;
using ComputerStoreContracts.ViewModels;
using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ComputerStoreBusinessLogic.BusinessLogic
{
    public class EmployeeLogic : IEmployeeLogic
    {
        private readonly ILogger _logger;
        private readonly IEmployeeStorage _employeeStorage;
        public EmployeeLogic(ILogger<EmployeeLogic> logger, IEmployeeStorage employeeStorage)
        {
            _logger = logger;
            _employeeStorage = employeeStorage;
        }
        public bool Create(EmployeeBindingModel model)
        {
            CheckEmployee(model);
            if (_employeeStorage.Insert(model) == null)
            {
                _logger.LogWarning("Insert operation failed");
                return false;
            }
            return true;
        }

        public bool Update(EmployeeBindingModel model)
        {
            CheckEmployee(model);
            if (_employeeStorage.Update(model) == null)
            {
                _logger.LogWarning("Update operation failed");
                return false;
            }
            return true;
        }

        public bool Delete(EmployeeBindingModel model)
        {
            CheckEmployee(model, false);
            _logger.LogInformation("Delete. ID:{ID}", model.ID);
            if (_employeeStorage.Delete(model) == null)
            {
                _logger.LogWarning("Delete operation failed");
                return false;
            }
            return true;
        }

        public EmployeeViewModel? ReadElement(EmployeeSearchModel model)
        {
            if (model == null)
            {
                throw new ArgumentNullException(nameof(model));
            }
            _logger.LogInformation("ReadElement. Username:{Username}.ID:{ ID}", model.Username, model.ID);
            var element = _employeeStorage.GetElement(model);
            if (element == null)
            {
                _logger.LogWarning("ReadElement element not found");
                return null;
            }
            _logger.LogInformation("ReadElement find. ID:{ID}", element.ID);
            return element;
        }

        public List<EmployeeViewModel>? ReadList(EmployeeSearchModel? model)
        {
            _logger.LogInformation("ReadList. Username:{Username}. ID:{ ID}", model?.Username, model?.ID);

            var list = model == null ? _employeeStorage.GetFullList() : _employeeStorage.GetFilteredList(model);

            if (list == null)
            {
                _logger.LogWarning("ReadList return null list");
                return null;
            }
            _logger.LogInformation("ReadList. Count:{Count}", list.Count);
            return list;
        }

        public void CheckEmployee(EmployeeBindingModel model, bool withParams = true)
        {
            if (model == null)
            {
                throw new ArgumentNullException(nameof(model));
            }
            if (!withParams)
            {
                return;
            }
            if (string.IsNullOrEmpty(model.Username))
            {
                throw new ArgumentNullException("Invalid username of user", nameof(model.Username));
            }
            if (string.IsNullOrEmpty(model.Password))
            {
                throw new ArgumentNullException("Invalid password of user", nameof(model.Password));
            }

            _logger.LogInformation("Client. Username:{ Username}. ID: { ID} ", model.Username, model.ID);

            var element = _employeeStorage.GetElement(new EmployeeSearchModel
            {
                Username = model.Username
            });

            if (element != null && element.ID != model.ID)
            {
                throw new InvalidOperationException("Employee with such username already exists.");
            }
        }
    }
}